package JZ;

public class JZ9 {
    public int JumpFloorII(int target) {
        int[] dp = new int[target+1];
        dp[1] = 1;
        dp[2] = 2;
        for (int i = 2; i < target+1; i++) {
            dp[i] = dp[i-1] + i + 1;
        }
        return dp[target];
    }
}